The use of transparent conductive coatings (TCCs) in high heat and harsh environments such as, for example, oven door applications is known. See, for example, U.S. Pat. Nos. 6,320,164; 6,235,343; 6,024,084; and 4,985,312, each of which is hereby incorporated herein by reference in its entirety. In general, a plurality of glass substrates inside the oven door helps absorb the heat generated in the interior of the oven during use and also helps reduce transmission of heat to the exterior surface of the oven door. In this regard, the TCC in an oven door helps the door to act as a heat barrier or heat sink. The ability for an oven door to act as a heat barrier or heat sink is needed in connection with self cleaning ovens, as the cook chamber of a self-cleaning oven may reach temperatures as high as 600 degrees C. during the self-cleaning process. The exterior surface of the oven door cannot reach this temperature and remain safe. For example, it is desirable to keep the exterior surface of an oven door below about 77 degrees C., more preferably below about 60 degrees C., and more preferably still lower.
While efficacious for many known layer systems, the use of sputter-coating has been known to result in mechanical durability qualities less than that achieved by known pyrolytic techniques. As a reverse function, however, sputter-coated systems often achieve better infrared reflectance than typical pyrolytic coatings. Also, sputter-coated glasses have generally been recognized as having superior optical and thermal performance characteristics than pyrolytically formed coatings, such as having improved coating uniformity, good emittance, and better solar performance characteristics.
Unfortunately, only combustion vapor deposition (CVD) pyrolytic coatings have been used for commercial oven door applications, since pyrolytic layer systems are durable enough to withstand the harsh environments of an oven including, for example, high temperatures, cleaning cycles, humidity, etc. However, it will be appreciated that if a sputter-coating technique could be devised for a particular coating system wherein the mechanical durability qualities of the sputter-coated system could approach or equal that of a pyrolytic technique, while at the same time achieving the enhanced benefits of sputter-coated technology, a significant step forward in the art would be made.
Thus, it will be appreciated that there is a need in the art for sputter-deposited layer systems that are capable of withstanding harsh environments. It also will be appreciated that there is a need in the art for sputter-deposited transparent conductive coatings (TCCs) that are capable of withstanding the harsh environments of ovens.
In certain example embodiments of this invention, a method of making a door for an oven is provided. An inner glass substrate and an outer glass substrate are provided, with the inner glass substrate being provided for an interior side of the door and the outer glass substrate being provided for an exterior side of the door. A first transparent conductive coating is disposed on a first surface of the inner glass substrate, with the first surface being farthest from the outer glass substrate. A second transparent conductive coating is sputter-deposited on a second surface of the inner glass substrate, with the second surface being closest to the outer glass substrate. The second transparent conductive coating includes a zirconium oxide protective overcoat. The inner and outer glass substrates are thermally tempered.
In certain example embodiments of this invention, an assembly used in the creation of an oven door is provided. An inner glass substrate and an outer glass substrate are provided. A first transparent conductive coating is supported by a first surface of the inner glass substrate, with the first surface being farthest from the outer glass substrate. A second sputter-deposited transparent conductive coating is supported by a second surface of the inner glass substrate, with the second surface being closest to the outer glass substrate. The second transparent conductive coating comprises: a first barrier layer of silicon nitride provided on the second substrate, a first nickel chromium inclusive contact layer provided on the first barrier layer, a silver-inclusive conductive layer provided on the first contact layer, a second nickel chromium inclusive contact layer provided on the conductive layer, and a second barrier layer of silicon nitride provided on the second contact layer, and a zirconium oxide protective overcoat provided on the second contact layer.
According to certain example embodiments, the first transparent conductive coating is disposed on the first surface of the inner glass substrate via sputtering, and the first transparent conductive coating includes a zirconium oxide protective overcoat. According to certain other example embodiments, the first transparent conductive coating is disposed on the first surface of the inner glass substrate via pyrolysis.
According to certain example embodiments, a middle glass substrate is located between the inner glass substrate and the outer glass substrate, and the middle glass substrate is thermally tempered. According to certain example embodiments, a third transparent conductive coating may be sputter-deposited on a third surface of the middle glass substrate, with the third surface being farthest from the outer glass substrate, and with the third transparent conductive coating includes a zirconium oxide protective overcoat.
The sputter-deposited transparent conductive coatings of certain example embodiments may comprise: a first barrier layer of silicon nitride provided on the substrate, a first nickel chromium inclusive contact layer provided on the first barrier layer, a silver-inclusive conductive layer provided on the first contact layer, a second nickel chromium inclusive contact layer provided on the conductive layer, a second barrier layer of silicon nitride provided on the second contact layer, and a protective overcoat comprising zirconium oxide provided on the second barrier layer.
The example embodiments described herein may be used to build an assembly or intermediate product, which may be built into an oven door, and the oven door may be built into an oven.
In certain example embodiments of this invention, a method of making a coated article comprising a coating supported by a substrate is provided. A transparent conductive coating is sputter-deposited on the substrate, with the transparent conductive coating comprising: a first barrier layer of silicon nitride provided on the substrate, a first nickel chromium inclusive contact layer provided on the first barrier layer, a silver-inclusive conductive layer provided on the first contact layer, a second nickel chromium inclusive contact layer provided on the conductive layer, a second barrier layer of silicon nitride provided on the second contact layer, and a protective overcoat comprising zirconium oxide provided on the second barrier layer. One or more of these coated articles may be built into an assembly or intermediate product, which may be built into an oven door, and the oven door may be built into an oven.
In certain example embodiments of this invention, an assembly used in the creation of an oven door is provided. An inner glass substrate and an outer glass substrate are provided. First and second middle glass substrates are provided between the inner and outer glass substrates. First, second, and third sputter-deposited transparent conductive coatings are respectively supported by surfaces of the inner glass substrate, the first middle glass substrate, and the second middle glass substrate that face towards the outer glass substrate. The first, second, and third sputter-deposited transparent conductive coatings each comprise: a first barrier layer of silicon nitride provided on the second substrate, a first nickel chromium inclusive contact layer provided on the first barrier layer, a silver-inclusive conductive layer provided on the first contact layer, a second nickel chromium inclusive contact layer provided on the conductive layer, a second barrier layer of silicon nitride provided on the second contact layer, and a zirconium oxide protective overcoat provided on the second contact layer.
In certain example embodiments of this invention, an assembly used in the creation of an oven door is provided. An inner glass substrate and an outer glass substrate are provided. First and second middle glass substrates are provided between the inner and outer glass substrates. First, second, and third transparent conductive coatings are respectively supported by both surfaces of the inner glass substrate and an outer surface of the first middle glass substrate. The third transparent conductive coating is a sputter-deposited transparent conductive coating. Either (a) the first transparent conductive coating is a sputter-deposited transparent conductive coating and the second transparent conductive coating is a pyrolytically disposed transparent coating, or (b) the second transparent conductive coating is a sputter-deposited transparent conductive coating and the first transparent conductive coating is a pyrolytically disposed transparent coating. Each said sputter-deposited transparent conductive coating comprises: a first barrier layer of silicon nitride provided on the second substrate, a first nickel chromium inclusive contact layer provided on the first barrier layer, a silver-inclusive conductive layer provided on the first contact layer, a second nickel chromium inclusive contact layer provided on the conductive layer, a second barrier layer of silicon nitride provided on the second contact layer, and a zirconium oxide protective overcoat provided on the second contact layer.
The features, aspects, advantages, and example embodiments described herein may be combined to realize yet further embodiments.